What is a Salt Marsh

1
What is a Salt Marsh?

• Salt marshes are transitional areas between land
  and water, occurring along the intertidal shore
  of estuaries and sounds where salinity (salt
  content) ranges from near ocean strength to near
  fresh in upriver marshes.

2
Where are seagrass and salt marsh communities
located?
Salt marshes
3
Estuarine Habitats
Salt marshes
Tidal channels
4
1. Open Water- Subtidal
Estuarine Habitats
Salt marshes
Tidal channels
Eelgrass beds
5
1. Open Water- Subtidal
Estuarine Habitats
2. Intertidal mudflat
Salt marshes
Tidal channels
Intertidal mudflat
Eelgrass beds
6
(No Transcript)
7
(No Transcript)
8
(No Transcript)
9
(No Transcript)
10
Undisturbed Salt Marsh Zonation
Transitional Zone
Lower Limit of Emergent Salt Marsh Vegetation
Mature High Salt Marsh
Low and Mid Salt Marsh
Mudflat
Mainstem Tidal Channel
11
Why are seagrass and salt marsh communities
important? What roles do they play in the
coastal ecosystem?
12
What kinds of plants live in tidal marshes?

• High elevation
• Mid-elevation
• Low-elevation

13
Gumweed (Grindelia integrefolia)
High marsh
14
Douglas Aster (Aster subspicatus)
High marsh
15
Fat Hen (Atriplex patula)
High marsh
16
Pacific SilverweedPotentilla pacifica
High marsh
17
Soft Rush (Juncus effusus)
High marsh
18
Lyngbys sedge (Carex lyngbei)
Mid marsh
19
Meadow Barley (Hordeum brachyantherum)
Mid marsh
20
Seaside Arrowgrass (Triglochin maritimum)
Mid marsh
21
Saltmarsh Birdsbeak (Cordylanthus maritimus)
Low marsh
22
Pickleweed (Salicornia virginica)
Low marsh
23
Fleshy Jaumea (Jaumea carnosa)
Low marsh
24
Saltmarsh Dodder (Cuscuta salina)
Low marsh
25
Salt Grass (Distichlis spicata)
Low marsh
26
Paintbrush Owlclover (Orthocarpus castillejoides)
Low marsh
27

• In ecological and economic value, they rival
  tropical rainforests and the worlds richest
  farmlands!

28
Seagrass and Salt Marsh Functions

• Primary Production
• Fish and Wildlife Habitat (including nursery
  role)
• Sediment sink
• Shoreline protection
• Water Quality

29
Primary Production
Eelgrass and Salt Marsh provide the critical
foundation to the detrital food web

• Production
• Shredding
• Colonization/decomposition
• Consumption by small organisms (grazers)
• Consumption by larger organisms (predators)
• Defecation/Nutrient transformation

30
Fish and Wildlife Habitat Example

• Juvenile Salmon rearing habitat
• Foraging
• Physiological transitions
• Refuge from predators

31
Fish and Wildlife Habitat Example

• Resident and migratory bird habitat
• Shorebirds feed on insects, fish, invertebrates
• Ducks and geese graze on vegetation Ex. Black
  Brant / eelgrass

32
Water Quality

• Nutrient uptake
• Sediment trapping and baffling of wave energy
• Oxygen production

33
Natural Variability of Salt Marsh and Seagrass
Habitats

• Plant distribution, species diversity, and
  density can vary substantially over seasons and
  years in response to
• Precipitation, water table
• Light availability
• Temperature
• Nutrient availability
• Plant competition/succession
• Sediment characteristics
• Oceanic cycles (El NIÑO, PDO)
• Sea level rise

34

• Human Impacts on Salt Marsh and Seagrass
• Direct Impacts
• Dredging
• Diking
• Draining
• Filling

• Indirect Impacts
• Pollution toxics,
• nutrients, sediments
• Water diversions
• Shading i.e. docks,
• piers, bridges, boats,
• high water turbidity
• Invasive species

35
HISTORIC CHANGES OF COOS BAY TIDAL WETLANDS,
FILLED AGRICULTURAL LANDS, AND RESIDENTIAL
COMMUNITIES (1892-1995)
ACRES
YEAR
36
Coos Bay 1900
37
Why Monitor Salt Marsh and Seagrass Habitat?

• To further our understanding of coastal ecology
• To document changes over time as an indicator of
  estuarine health
• To assess changes in sensitive estuarine
  habitats from long term trends in sea
  level rise and climate change
• To alert us to declines in key habitats and
  guide corrective action
• To motivate the public to protect existing
  habitat, restore degraded habitat, and improve
  upstream land use practices

38
Transects and Plots
39
What do we measure at each site?

• Water depth
• Water salinity (salt content)

• Water Table Height
• Sediment elevation changes
• Sediment grain size
• Light using loggers
• Water temperature using loggers

40
(No Transcript)